Faculty Collaboration Database

A chimeric platelet-targeted urokinase prodrug selectively blocks new thrombus formation. J Clin Invest 2016 Feb;126(2):483-94

Date

12/23/2015

Pubmed ID

26690701

Pubmed Central ID

PMC4731161

DOI

10.1172/JCI81470

Scopus ID

2-s2.0-84956924316 (requires institutional sign-in at Scopus site)   24 Citations

Abstract

The use of fibrinolytic agents to prevent new thrombus formation is limited by an increased risk of bleeding due to lysis of hemostatic clots that prevent hemorrhage in damaged blood vessels. We sought to develop an agent that provides thromboprophylaxis without carrying a significant risk of causing systemic fibrinolysis or disrupting hemostatic clots. We previously showed that platelet (PLT) α granule-delivered urokinase plasminogen activator (uPA) is highly effective in preventing thrombosis, while being associated with little systemic fibrinolysis or bleeding. Here, we generated a chimeric prodrug composed of a single-chain version of the variable region of an anti-αIIbβ3 mAb fused to a thrombin-activatable, low-molecular-weight pro-uPA (PLT/uPA-T). PLT/uPA-T recognizes human αIIbβ3 on both quiescent and activated platelets and is enzymatically activated specifically by thrombin. We found that this prodrug binds tightly to human platelets even after gel filtration, has a prolonged half-life in mice transgenic for human αIIb compared with that of uPA-T, and prevents clot formation in a microfluidic system. Importantly, in two murine injury models, PLT/uPA-T did not lyse preexisting clots, even when administration was delayed by as little as 10 minutes, while it concurrently prevented the development of nascent thrombi. Thus, PLT/uPA-T represents the prototype of a platelet-targeted thromboprophylactic agent that selectively targets nascent over preexisting thrombi.

Author List

Fuentes RE, Zaitsev S, Ahn HS, Hayes V, Kowalska MA, Lambert MP, Wang Y, Siegel DL, Bougie DW, Aster RH, Myers DD, Stepanova V, Cines DB, Muzykantov VR, Poncz M

MESH terms used to index this publication - Major topics in bold

Animals
Blood Platelets
Drug Delivery Systems
Humans
Mice
Mice, Inbred NOD
Mice, Knockout
Mice, SCID
Prodrugs
Recombinant Fusion Proteins
Thrombosis
Urokinase-Type Plasminogen Activator